If the firms failed to make enough money , they would .
A. close down
B. call off
C. turn down
D. set off
网友回答
(答案→)A. close down
B. call off
C. turn down
D. set off
解析：考查短语辨析。close down 关闭，call off 取消，turn down 拒绝，set off 出发，句意：如果这些公司不能挣足够的钱，它们就会关闭。所以选A。